redis 简单分布式锁dome

╰+哭是因爲堅強的太久メ 2024-03-27 13:39 70阅读 0赞

### redis 简单分布式锁dome ###

import org.springframework.beans.factory.annotation.Value;
    import org.springframework.data.redis.core.StringRedisTemplate;
    import org.springframework.stereotype.Component;
    
    import javax.annotation.Resource;
    import java.net.InetAddress;
    import java.net.UnknownHostException;
    import java.util.concurrent.TimeUnit;
     
    @Component
    public class DistrbutedLockUtil {
        
        @Resource
        private StringRedisTemplate stringRedisTemplate;
    
        @Value("${server.port}")
        private String port;
    
        /**
         * 上锁
         *
         * @param key     键  （要唯一）
         * @param timeout 时间大小
         * @param unit    时间颗粒度 （时分秒....）
         * @return
         */
        public boolean lock(String key,  long timeout, TimeUnit unit) throws UnknownHostException {
        
            String ip = InetAddress.getLocalHost().getHostAddress() + ":" + port;
            return stringRedisTemplate.opsForValue().setIfAbsent(key, ip, timeout, unit);
        }
    
        /**
         * 解锁
         * @param key 键 （上锁的值）
         */
        public void unlock(String key) {
        
            if ("".equals(key)) {
        
                System.out.println("没有锁，不需要锁释锁！");
            } else {
        
                String str = stringRedisTemplate.delete(key) == true ? "锁释放成功" : "锁释放失败";
                System.out.println(key + str);
            }
        }
    
    }

import javax.annotation.Resource;
    import java.text.SimpleDateFormat;
    import java.util.Calendar;
    import java.util.Date;
    import java.util.UUID;
    import java.util.concurrent.TimeUnit;
    
    @Component
    public class DomeTask1 {
        
    
        @Autowired
        private DistrbutedLockUtil distrbutedLockUtil;
    
        @Scheduled(cron = "0 */1 * * * ?")
        public void dome() throws Exception {
        
            String key = "dome";
            //设置锁
            try {
        
                Boolean flagLock = distrbutedLockUtil.lock(key,30,TimeUnit.SECONDS);
                if (!flagLock) {
        
                    key = "";
                    System.out.println("-----抢redis锁失败-----");
                } else {
        
                    System.out.println("-----抢redis锁成功-----");
                    //抢锁成功后的业务操作：
                    Date now2 = Calendar.getInstance().getTime();
                    SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                    //操作完毕，释放锁,在return前释放
                    System.out.println(format1.format(now2) + " 在这里执行定时任务的业务.....");
                    Thread.sleep(20000);
                    System.out.println("-----业务执行完成-----");
                }
            } finally {
        
                distrbutedLockUtil.unlock(key);
            } 
        } 
    }